Noncorrosive graphite emulsions



In like Patented Oct. 26, 1954 UNITEZDj STAT 2569.2,857 N ONCORROSIVE GRAPHITE EMULSION S Josef Michel and" Karl F. Hager, Huntsville,

Alau, and Morris Rosenthal, Alexandria, Va.,

assignors,

by direct-and mesne assignments, to

the United- States of: Americaasrepresented by: the Secretary'ofthe Army N '0 Drawing. Application January 19, 1951,

Serial No. 206,931

I Claims.- 1.

This'invention relates to non-corrosive aqueous suspensions of graphite useful as lubricants;

Graphite has long been known as an excellent lubricant. It has been used alone or as a dispersion in oil with good results. In many cases however the use of oil. as a diluent must be avoided because of the hazard of inflammability; especially wherehigh temperatures or' oxygen are involved. Under the latter conditions suspensions of graphite in water have been found suitable. These.- graphitei-water. dispersions. permit the easy lubrication even of oxygen valves built from light metal but the water content causescorrosion of the'metal with which it'comes in contact.

Methods heretofore known for. preventing corrosion by a water phase have been of no use with the graphite-water dispersion. The admixture of inorganic salts suchas-sodium nitrite has been tried' but without the production of any. particularly beneficial results. Instead, this addition has merely caused the deposit of crystals upon the metallic surface when the 'waterevaporated'. manner the addition of organic amines fails to prevent corrosion: of light metals; It" is accordingly the principal object of'this-invention to develop a method of preventing the corrosive efiect of graphite-water lubricatmg: emulsions upon metals and especially upon light or'nonferrous metals.

A non-corroding graphite-water mixture can be obtained by adding'to the ordinary emulsion az small amount of a compoundrof the'composition:

tion without ahaza-rdous oily layer-on the lubricated surface.

The following examples are given to illustrate the effects of the-addition of'the'corrosiveresisting agents in the manner of the present invention:

Eramplel The. parts of alightmetal valve regulatinga flow of liquid oxygen-were lubricated" with a graphite-oil paste. Under active working conditions an explosion-like inflammation of the oil film occurred, burning out the valve.

a length of 2. Example 2 A valve similar in construction to that of- Ex ample 1 was lubricated with agraphite-water paste. After evaporation of the water content, the valve worked safely in contact with oxygen. Corrosion, however, was visible on the light metal parts.

Example 3' The lubrication of Example 2 was repeated'except that thegraphite-water paste applied contained 0.1% of octadecyl-sulfamido acetic acid sodium salt. The light metal valve worked safe- 1y in contact with oxygen with no corrosion at all.

Eitample 4.

The highly polishedsurf'ace of metal dies used to cure rubber was covered with a graphite-water paste containing 0.5% by" weight of hexadecyl sulfamido butyric acid potassium salt. No corrosion occurred duringfa long storage period'and the dies could be usedinst'antaneously without cleaning.

Example 5 On the elevator blades of a rocket stagnation temperatures of about 400.' C. have been observed. A lubricant of usual be'used at this temperature because of its. inflammability and lack of heat resistance. A water graphite mixture containing 0.5%

inhibitor acted as a sufliciently heat resistive lubricant but causedno corrosion to the blades after along storage time: R3 in this formula represents a: saturated aliphatic. hydrocarbon radical with a chainlengthof between l2.and 18 carbon atoms.

The foregoing examples merely illustrate the advantages of the present'invention which is limited. solely by the scope: of the appended claims.

What we claimis:

1. The method of inhibiting the corrosive properties of a suspensionof graphite in water which comprises supplying thereto a minor corrosion. inhibiting amount' of. a compound of the formula where. R1 represents a saturated aliphatic hydrocarbon radical'with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from' thegroup consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

composition cannot.

2. A composition of matter comprising water as a dispersing and solvent medium, graphite colloidally suspended in the water, and a minor corrosion inhibiting amount of a dissolved compound of the formula where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

3. A composition of matter comprising water, graphite colloidally dispersed therein and a minor corrosion inhibiting amount of dissolved octadecyl-sulfamido acetic acid sodium salt.

4. A composition of matter comprising water, graphite colloidally dispersed therein and a minor corrosion inhibiting amount of hexadecylsulfamido butyric acid potassium salt.

5. A composition of matter comprising water, graphite colloidally dispersed therein and a minor corrosion inhibiting amount of a com pound of the formula where R3 represents a saturated aliphatic hydrocarbon radical with a chain length of between 12 and 18 carbon atoms.

6. A lubricant comprising water, colloidally dispersed graphite and a minor corrosion inhibiting amount of a dissolved compound of the formula where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

7. The method of inhibiting the corrosive properties of a suspension of graphite in water which comprises supplying thereto between about 0.1% and about 0.5% of a compound of the formula where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

8. The method of protecting light metals against the corrosive attack of a water-graphite paste which consists in supplying to said paste between about 0.1% and 0.5% by weight of a compound of the formula where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

9. A composition of matter consisting essen- 4 'tially of water as a dispersing and solvent medium, graphite colloidally suspended in the water, and a minor corrosion inhibiting amount of a dissolved compound of the formula where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

10. A composition of matter consisting essentially of water as a dispersing and solvent medium, graphite colloidally suspended in the water and between about 0.17% and about 0.5% by weight of a dissolved compound of the formula Where R1 represents a saturated aliphatic hydrocarbon radical with a chain length of between eight and twenty-four carbon atoms and R2 represents a member chosen from the group consisting of aliphatic and aromatic carboxylic acid radicals of low molecular weight and the water soluble salts thereof.

11. A composition of matter consisting essentially of water, graphite colloidally dispersed therein and between about 0.1% and 0.5 of dissolved hexadecyl sulfamido butyric acid potassium salt.

12. A lubricant consisting essentially of a graphite-water paste containing 0.1% by weight of octadecyl-sulfamido acetic acid sodium salt.

13. A lubricant consisting essentially of a graphite-water paste containing 0.5% by weight of hexadecyl sulfamido butyric acid potassium salt.

14. A lubricant non-corrosive towards light metals consisting essentially of a graphite-water paste carrying dissolved therein between about 0.1% and 0.5% by weight of a compound of the formula References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 986,793 Acheson Mar. 11, 1911 1,784,220 Broeman Dec. 9, 1930 1,944,273 Rutherford Jan. 23, 1934 2,090,263 Moses Aug. 17, 1937 2,236,168 Dietrich Mar. 25, 1941 2,249,800 Weber July 22, 1941 2,602,760 Michel et al. July 8, 1952 

2. A COMPOSITION OF MATTER COMPRISING WATER AS A DISPERSING AND SOLVENT MEDIUM, GRAPHITE COLLOIDALLY SUSPENDED IN THE WATER, AND A MINOR CORROSION INHIBITING AMOUNT OF A DISSOLVED COMPOUND OF THE FORMULA @SP RI-SO2-NH-R2 @SP WHERE R1 REPRESENTS A SATURATED ALIPHATIC HYDROCARBON RADICAL WITH A CHAIN LENGTH OF BETWEEN EIGHT AND TWENTY-FOUR CARBON ATOMS AND R2 REPRESENTED A MEMBER CHOSEN FROM THE GROUP CONSISTING OF ALIPHATIC AND AROMATIC CARBOXYLIC ACID RADICALS OF LOW MOLECULAR WEIGHT AND THE WATER SOLUBLE SALTS THEREOF. 